<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script type="text/javascript">
			document.write("<h1 align='center'>打印倒正金字塔直线</h1>");
			var rr=prompt("请输入行高");
			var r = parseInt(rr/2);
			for (var i=r+1;i>0;i--) {
				document.write("<hr width="+(i*2-1)*40+ "px;size='3' color='red'/>");
				
			}
			for (var j=1;j<=r;j++) {
				document.write("<hr width="+(j*2+1)*40+ "px;size='3' color='red'/>");
			}
		
		</script>
	</head>
	<body>
	</body>
</html>
